If the air detector alarms and foam is visible in the venous drip chamber, the immediate action is to:

• A. Notify the supervisor
• B. Clamp the venous line
• C. Increase dialysate flow
• D. Reassure the patient

Answer: (B)

The main idea is to stop any air from entering the patient as quickly as possible. When the air detector alarm sounds and foam is seen in the venous drip chamber, air is likely in the venous portion of the circuit. Clamping the venous line immediately isolates the patient from the circulating blood and stops the potential air embolism from reaching you or the patient. Once the line is clamped, you can purge the circuit and inspect for the source of the air, then resume safe operation after ensuring there is no air in the line.

Choosing another action isn’t as effective right away: notifying a supervisor doesn’t stop the immediate hazard; increasing dialysate flow could push air toward the patient; and reassuring the patient doesn’t address the actual risk of air embolism.